From a psychological point of view seperating thought waves is possible. But nothing is really "seperated". Rather the concsiousness is just in an altered state of mind. That and the brain isn't really producing "waves" in the first place. Its just we call them that because when monitored on an EEG machine that measures electrical activity, what is produced looks like a wave pattern.
I took intro to neuro-psychology a while back (while back meaning its not entirely fresh in my brain). But basically you have six major kinds of brains waves (this
article from wikipedia will help illustrate what I am saying) The following is a brief overview of these and where in the brain the occur:
Beta waves are actually what is measured from the brain during normal activity. It is when we are most alert and active. It is not the brain wave pattern ascribed to ESP or supernatural abilities. It is associated with the areas of the brain that are active when one is concsentrating (as in doing one task, like reading or running).
Alpha waves can be measured when a person is relaxed, especially when one goes to bed and they close their eyes, initiating the sleep cycle. Alpha waves can be seen in basic meditation as well. These are associated with the back of the brain, mainly the occipital lobe (where visual sensory information is processed). When one is relaxed and able to think clearly, this is the state of mind where one can easily image things in detail as well.
Mu waves (Mu rhythm) are the brain waves associated with any kind of movement. Any Mu wave will originate from the motor cortex (the thing that controls movement).
Theta waves are measured when the brain is deeply relaxed or focused. You mainly experience theta waves during deep meditation and sleep. Theta waves have been linked to perception and cognition as well as creativity, memory recall, learning and spatial reasoning. The area of the brain that produces these waves is the hippocampus. This is the area where basic memory and spatial reasoning take place.
Delta waves are most commonly visible during unconcsious, deep sleep and small children. It is not normal to experience a delta state while awake. It could be a sign of possible health problems, including schizophrenia or brain damage. In adults delta waves are measured largely from activity occuring in the frontal lobe.
Gamma waves are bit more controversal. Not all scientist agree they should be a seperate class. They are similar to beta waves, only they are associated with higher electrical activity. Some speculate these waves are what one generates when they experience periods of clarivoyance or other forms of ESP. They do occur when the mind is engaged in higher forms of mental activity (like reading or drawing or attempting to shoot a free throw during a basket ball game.
You can experience these waves (or rhythms) through progressive and guided meditations as well as path working rituals, lucid dreaming and astral projection. Bio-feedback devices have been shown to work as well.